In log4net we can change the log level in the xml config file on runtime from DEBUG to ERROR for example and the change take effect immediately.
is there a way to do it in python? i haven't figured out yet how to do it.
In addition, for some reason, when the logging file is set without any folder (see example of the config i use at the bottom - yaml dictionary config file), it fails to rotate files. if i change it to be at any other path other the one that the code is in, it works like a charm and 20 files get created.
i will be happy to get any help.
thanks!
dictionary config extract example:
rotatingFile:
class : logging.handlers.RotatingFileHandler
formatter: jajahFormater
level: DEBUG
filename: chs.log
maxBytes: 20
backupCount: 20
You really should have posted two questions.
The .NET infrastructure watches the config file and automatically loads it to get the changes, but Python doesn't - so you would need to code this yourself.
The chs.log file in the code directory may be held open (e.g. in an editor), which would prevent rollover - I can't tell without more information.
From the docs use Logger.setLevel() at logger level and Handler.setLevel() at handler level
import logging
my_logger = logging.getLogger('myloggername') #Assumes you have configured the logger somewhere
my_logger.setLevel(logging.INFO)
Related
I've seen some very odd behaviour with the logger module. It started with a relatively complex project, but now I've seen it with the following script:
import logging
import os
# Uncomment the following line to remove handlers
# logging.getLogger().handlers = []
filePath = os.environ['userprofile'] + r'\Documents\log.txt'
logging.basicConfig(filename=filePath)
logging.debug('Gleep')
logging.shutdown()
This should simply write 'Gleep' to the log.txt file to your documents. Currently it is writing the file but not writing anything to it, however, I've inconsistently seen the following behaviour:
List item
No log file being written at all.
Log file created, but nothing written to it.
Everything working fine.
The only way I've got it working before is to remove existing handlers (commented out in the example above).
This is on several machines in different locations.
So...am I doing something grotesquely wrong here? Why is the logging module acting this way?
I'm not sure how to prove/disprove/debug your 'other' situations, but maybe the following can help clarify what is happening in the code from your question:
First, setting logging.getLogger().handlers = [] should not be necessary, since logging.getLogger() is the root logger by default and has no handlers. Here is a fresh Python 3.7 shell:
>>> import logging
>>> logging.getLogger()
<RootLogger root (WARNING)>
>>> logging.getLogger().handlers
[]
(Note that in the absence of any handlers, a logger will fall back to lastResort, but that should be irrelevant here since you add a handler implicitly via basicConfig().)
Which brings you to logging.basicConfig(filename=filePath): this adds a FileHandler handler to the root logger. It does not touch the level of the root logger, which is WARNING by default, so your message won't pass the 'level test' and won't be emitted as a result.
>>> logging.root.getEffectiveLevel()
30
(This uses .getEffectiveLevel() rather than just the plain attribute because a logger will walk its hierarchy until it finds a level if its level is NOTSET.)
All that is to say: as you currently have it, you are logging from the root logger (level WARNING) a message object that has level DEBUG, so the message will go nowhere.
I am working with the Python logging module but I don't know how get writing in different files for each type of logging level.
For example, I want the debug-level messages (and only debug) saved in the file debug.log.
This is the code I have so far, I have tried with handlers but does not work anymore. I don't know If it is possible to do so I wish. This is the code I have using handlers and different files for each level of logging, but it does not work, since the Debug file save messages of all other levels.
import logging as _logging
self.logger = _logging.getLogger(__name__)
_handler_debug = _logging.FileHandler(self.debug_log_file)
_handler_debug.setLevel(_logging.DEBUG)
self.logger.addHandler(_handler_debug)
_handler_info = _logging.FileHandler(self.info_log_file)
_handler_info.setLevel(_logging.INFO)
self.logger.addHandler(_handler_info)
_handler_warning = _logging.FileHandler(self.warning_log_file)
_handler_warning.setLevel(_logging.WARNING)
self.logger.addHandler(_handler_warning)
_handler_error = _logging.FileHandler(self.error_log_file)
_handler_error.setLevel(_logging.ERROR)
self.logger.addHandler(_handler_error)
_handler_critical = _logging.FileHandler(self.critical_log_file)
_handler_critical.setLevel(_logging.CRITICAL)
self.logger.addHandler(_handler_critical)
self.logger.debug("debug test")
self.logger.info("info test")
self.logger.warning("warning test")
self.logger.error("error test")
self.logger.critical("critical test")
And the debug.log contains this:
debug test
info test
warning test
error test
critical test
I'm working with classes, so I have adapted a bit the code
Possible duplicate to: python logging specific level only
Please see the accepted answer there.
You need to use filters for each handler that restrict the output to the log level supplied.
I have created a logger called userlog:
self.ulog = logging.getLogger('userlog')
Then added a file handler
handler=logging.FileHandler(fileLoc,'w')
self.ulog.addHandler(handler)
But all logging calls to ulog also appear in the log specified by the defaultConfig of the python logging library, how do I have these lines not appear in the default log, and only in the file specified by the handler?
Set the self.ulog.propagate property to False.
Look at the Logger documentation for more details: http://docs.python.org/2/library/logging.html#logging.Logger.propagate
I want to output some strings to a log file and I want the log file to be continuously updated.
I have looked into the logging module pf python and found out that it is
mostly about formatting and concurrent access.
Please let me know if I am missing something or amy other way of doing it
usually i do the following:
# logging
LOG = "/tmp/ccd.log"
logging.basicConfig(filename=LOG, filemode="w", level=logging.DEBUG)
# console handler
console = logging.StreamHandler()
console.setLevel(logging.ERROR)
logging.getLogger("").addHandler(console)
The logging part initialises logging's basic configurations. In the following I set up a console handler that prints out some logging information separately. Usually my console output is set to output only errors (logging.ERROR) and the detailed output in the LOG file.
Your loggings will now printed to file. For instance using:
logger = logging.getLogger(__name__)
logger.debug("hiho debug message")
or even
logging.debug("next line")
should work.
Doug Hellmann has a nice guide.
To add my 10cents with regards to using logging. I've only recently discovered the Logging module and was put off at first. Maybe just because it initially looks like a lot of work, but it's really simple and incredibly handy.
This is the set up that I use. Similar to Mkinds answer, but includes a timestamp.
# Set up logging
log = "bot.log"
logging.basicConfig(filename=log,level=logging.DEBUG,format='%(asctime)s %(message)s', datefmt='%d/%m/%Y %H:%M:%S')
logging.info('Log Entry Here.')
Which will produce something like:
22/09/2015 14:39:34 Log Entry Here.
You can log to a file with the Logging API.
Example: http://docs.python.org/2/howto/logging.html#logging-to-a-file
I think there was a default log file, but I didn't find it yet.
Sometimes the HTTP request process would throw an exception on the screen, but I suggest it also goes somewhere on the disk or I wouldn't know what was wrong during a long run test.
P.S.: write an exception handler is another topic; first I'd like to know my question's answer.
I found something here:
https://groups.google.com/forum/?fromgroups=#!topic/python-tornado/px4R8Tkfa9c
But it also didn't mention where can I find those log.
It uses standard python logging module by default.
Here is definition:
access_log = logging.getLogger("tornado.access")
app_log = logging.getLogger("tornado.application")
gen_log = logging.getLogger("tornado.general")
It doesn't write to files by default. You can run it using supervisord and define in supervisord config, where log files will be located. It will capture output of tornado and write it to files.
Also you can think this way:
tornado.options.options['log_file_prefix'].set('/opt/logs/my_app.log')
tornado.options.parse_command_line()
But in this case - measure performance. I don't suggest you to write to files directly from tornado application, if it can be delegated.
FYI: parse_command_line just enables pretty console logging.
With newer versions, you may do
args = sys.argv
args.append("--log_file_prefix=/opt/logs/my_app.log")
tornado.options.parse_command_line(args)
or as #ColeMaclean mentioned, providing
--log_file_prefix=PATH
at command line
There's no logfile by default.
You can use the --log_file_prefix=PATH command line option to set one.
Tornado just uses the Python stdlib's logging module, if you're trying to do anything more complicated.
Use RotatingFileHandler:
import logging
from logging.handlers import RotatingFileHandler
log_path = "/path/to/tornado.access.log"
logger_ = logging.getLogger("tornado.access")
logger_.setLevel(logging.INFO)
logger_.propagate = False
handler = RotatingFileHandler(log_path, maxBytes=1024*1024*1024, backupCount=3)
handler.setFormatter(logging.Formatter("[%(name)s][%(asctime)s][%(levelname)s][%(pathname)s:%(lineno)d] > %(message)s"))
logger_.addHandler(handler)